The invention relates to a two-step process for the production of N-substituted morpholine and piperidine derivatives of the formula ##STR7## wherein R.sub.2, R.sub.3, R.sub.4 and R.sub.5 each is independently hydrogen, methyl or ethyl and X is O or CH.sub.2 and to the bromination reaction employed therein.
Conventional syntheses of N-substituted morpholine and piperidine derivatives of Formula I exist. DE-Pat. No. 26 56 747=CA-Pat. No. 1 086 734=GB-Pat. No. 1 591 267 describes a process for the production of morpholine derivates wherein 3-p-tert-butylphenyl-2-methylpropanal is reacted with 2,6-dimethylmorpholine in the presence of formic acid. A disadvantage in this and similar processes is the use of 3-p-tert-butylphenyl-2-methylpropanal which is expensive and which, in turn, is prepared from p-tert-butyl-benzaldehyde, which is technically accessible only with difficulties, by aldolization with propionaldehyde and subsequent selective hydrogenation of the double bond in the aldolization product.
EP-Pat. No. 0 005 541=AU-Pat. No. 79/46909=ZA No. 79/2242 demonstrates that substituted morpholine and piperidine derivates are easily preparable with the aid of bromides corresponding to the following formula (see in this connection, Example 10): ##STR8## wherein R.sub.1 is H or a C.sub.1 -C.sub.4 alkyl group. The bromides, however, are synthesized from the corresponding alcohols with phosphorus tribromide. The alcohols are also prepared in a multistage synthesis starting with p-tert-butylbenzaldehyde which is technically accessible only with difficulties. All known methods for the production of the morpholine and piperidine derivatives of Formula I, which are substituted in the para-position thus start with the expensive and technically poorly accessible p-alkyl benzaldehydes, e.g., p-tert-butylbenzaldehyde.
A process would be desirable which makes possible the preparation of the bromine compounds above starting with inexpensive chemicals in conventional industrial apparatus. There is great interest in such a process by which, with low technical expenditure and without the use of costly reagents, N-substituted morpholine and piperidine derivatives can be produced, because these products have great economic importance, for example, as fungicides (GB-Pat. No. 1 591 267 and DE-No. OS 31 01 233=EP-Pat. No. 0 056 461).